Chloroplasts preparation

Chloroplasts will be isolated from spinach leaves and used to explore some intricacies of proton transport and photophosphorylation. The chloroplast preparation should be used as soon as possible (within 2 to 3 hours) since biological activity will decrease with time. The experimental apparatus for... 

Chloroplast preparation from part A 80% acetone solution in water Conical centrifuge tube Glass cuvette, one pair... 

Design a flowchart outlining the chloroplast preparation procedure ami describe the purpose of each step. 

B 8. A student in the lab completes part B of this experiment to measure the chlorophyll content of the chloroplast preparation. The final A652 of the 80°/o acetone extract was 0.13. What is the concentration of chlorophyll in mg/mL in the chloroplast preparation ... 

Incubation of a crude chloroplast preparation with cadaverine yielded lupanine... 

Fig. 3. Left EPR spectra of membrane-bound iron-sulfur proteins reduced by dithionite and methyl viologen. HP700 particles from spinach (A), soybean (B) and Anabaena chloroplasts (C). Spectra D and E are for chloroplasts prepared from mutant No. 8 of Scenedesmus obliquus and for TSF-IIa particles, respectively. Right plot of the EPR-signal amplitude at g=2.05 due to reduced iron-sulfur-protein vs. the P700 concentration in chloroplast and subchloroplast samples from various sources (1, unfractionated chloroplasts 2, D144 particles 3, TSF-1 particles 4. D144 from stroma 5, D144 from grana 6, HP700 particles 7, HP700 particles from soybean 8, chloroplasts from Anabaena 9, chloroplasts from mutant No. 8 of Scenedesmus obliquus-, and 10, TSF-2a particles. Unpublished results of B Ke and H Beinert (1973).

The first measurement which we made on the model system, namely, the conductivity, is the most difficult to make on this type of biological material because the lamella of the chloroplasts are very small (30 to 60 A thick). However, there have been conductivity measurements on dried chloroplast preparations which show that they are indeed photo-conductive. Although these are subject to questionable interpretation in such a complex system (39, 40), the photoconductive behavior of a chromatophore film is shown in Fig. 15. 

A student m the lab completes part B of this experiment to measure the chlorophyll content of the chloroplast preparation. The final... 

Clostridial ferredoxin is also photo-reduced by chloroplast preparations, and it is one of the chief reasons why the name ferredoxin has been used interchangeably for both the 8-iron-8 sulfur protein and the 2-iron-... 

Tjus S, Andersson B. Loss of the trans-thylakoid proton gradient is an early event during photoinhibitory illumination of chloroplast preparations. Biochim Biophys Acta 1993 1183(2) 315-322. 

Chloroplasts have been prepared from spinach. The ATP-synthase was brought into the active, reduced state by illumination in the presence of thioredoxin and dithiothreitol. Washing of the chloroplasts drastically reduced the content of endogeneous ADP and ATP. Then, the ATP-synthases are activated by a ApH/Areduced state and contain no enzyme-bound ADP and only one enzyme-bound ATP per CFqFq. The maximum rate of ATP hydrolysis (at 1 mM ATP, pH 8.2) is about 100 before and after the washing. The enzyme remains in the active state for about 450 s (half-life time). All following experiments are carried out with such chloroplasts preparations. 

Antigen Chloroplast preparation of J, tabacum var. JWB Su, N. tabacum Su/su Sa, tabacum Su/su var. Aurea Sp, Spinacia oleracea. Antiserum AS, mixed antiserum to RuBP carboxylase/oxygenase of tabacum var. JWB and of tabacum Su/su, 1.4% serum in the gel ASo, mixed antiserum to RuBP carboxylase/oxygenase of tabacum var. JWB and of Spinacia oleracea A, antiserum to RuBP carboxylase/oxygenase of N. tabacum var. JWB... 

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